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Diffstat (limited to 'net/llc/llc_pdu.c')
| -rw-r--r-- | net/llc/llc_pdu.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/net/llc/llc_pdu.c b/net/llc/llc_pdu.c new file mode 100644 index 00000000..2e6cb791 --- /dev/null +++ b/net/llc/llc_pdu.c @@ -0,0 +1,372 @@ +/* + * llc_pdu.c - access to PDU internals + * + * Copyright (c) 1997 by Procom Technology, Inc. + * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * + * This program can be redistributed or modified under the terms of the + * GNU General Public License as published by the Free Software Foundation. + * This program is distributed without any warranty or implied warranty + * of merchantability or fitness for a particular purpose. + * + * See the GNU General Public License for more details. + */ + +#include <linux/netdevice.h> +#include <net/llc_pdu.h> + +static void llc_pdu_decode_pdu_type(struct sk_buff *skb, u8 *type); +static u8 llc_pdu_get_pf_bit(struct llc_pdu_sn *pdu); + +void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 pdu_type) +{ + llc_pdu_un_hdr(skb)->ssap |= pdu_type; +} + +/** + * pdu_set_pf_bit - sets poll/final bit in LLC header + * @pdu_frame: input frame that p/f bit must be set into it. + * @bit_value: poll/final bit (0 or 1). + * + * This function sets poll/final bit in LLC header (based on type of PDU). + * in I or S pdus, p/f bit is right bit of fourth byte in header. in U + * pdus p/f bit is fifth bit of third byte. + */ +void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value) +{ + u8 pdu_type; + struct llc_pdu_sn *pdu; + + llc_pdu_decode_pdu_type(skb, &pdu_type); + pdu = llc_pdu_sn_hdr(skb); + + switch (pdu_type) { + case LLC_PDU_TYPE_I: + case LLC_PDU_TYPE_S: + pdu->ctrl_2 = (pdu->ctrl_2 & 0xFE) | bit_value; + break; + case LLC_PDU_TYPE_U: + pdu->ctrl_1 |= (pdu->ctrl_1 & 0xEF) | (bit_value << 4); + break; + } +} + +/** + * llc_pdu_decode_pf_bit - extracs poll/final bit from LLC header + * @skb: input skb that p/f bit must be extracted from it + * @pf_bit: poll/final bit (0 or 1) + * + * This function extracts poll/final bit from LLC header (based on type of + * PDU). In I or S pdus, p/f bit is right bit of fourth byte in header. In + * U pdus p/f bit is fifth bit of third byte. + */ +void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit) +{ + u8 pdu_type; + struct llc_pdu_sn *pdu; + + llc_pdu_decode_pdu_type(skb, &pdu_type); + pdu = llc_pdu_sn_hdr(skb); + + switch (pdu_type) { + case LLC_PDU_TYPE_I: + case LLC_PDU_TYPE_S: + *pf_bit = pdu->ctrl_2 & LLC_S_PF_BIT_MASK; + break; + case LLC_PDU_TYPE_U: + *pf_bit = (pdu->ctrl_1 & LLC_U_PF_BIT_MASK) >> 4; + break; + } +} + +/** + * llc_pdu_init_as_disc_cmd - Builds DISC PDU + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * + * Builds a pdu frame as a DISC command. + */ +void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit) +{ + struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_U; + pdu->ctrl_1 |= LLC_2_PDU_CMD_DISC; + pdu->ctrl_1 |= ((p_bit & 1) << 4) & LLC_U_PF_BIT_MASK; +} + +/** + * llc_pdu_init_as_i_cmd - builds I pdu + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * @ns: The sequence number of the data PDU + * @nr: The seq. number of the expected I PDU from the remote + * + * Builds a pdu frame as an I command. + */ +void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_I; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= (p_bit & LLC_I_PF_BIT_MASK); /* p/f bit */ + pdu->ctrl_1 |= (ns << 1) & 0xFE; /* set N(S) in bits 2..8 */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_rej_cmd - builds REJ PDU + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * @nr: The seq. number of the expected I PDU from the remote + * + * Builds a pdu frame as a REJ command. + */ +void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_CMD_REJ; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= p_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_rnr_cmd - builds RNR pdu + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * @nr: The seq. number of the expected I PDU from the remote + * + * Builds a pdu frame as an RNR command. + */ +void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_CMD_RNR; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= p_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_rr_cmd - Builds RR pdu + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * @nr: The seq. number of the expected I PDU from the remote + * + * Builds a pdu frame as an RR command. + */ +void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_CMD_RR; + pdu->ctrl_2 = p_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_sabme_cmd - builds SABME pdu + * @skb: Address of the skb to build + * @p_bit: The P bit to set in the PDU + * + * Builds a pdu frame as an SABME command. + */ +void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit) +{ + struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_U; + pdu->ctrl_1 |= LLC_2_PDU_CMD_SABME; + pdu->ctrl_1 |= ((p_bit & 1) << 4) & LLC_U_PF_BIT_MASK; +} + +/** + * llc_pdu_init_as_dm_rsp - builds DM response pdu + * @skb: Address of the skb to build + * @f_bit: The F bit to set in the PDU + * + * Builds a pdu frame as a DM response. + */ +void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit) +{ + struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_U; + pdu->ctrl_1 |= LLC_2_PDU_RSP_DM; + pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK; +} + +/** + * llc_pdu_init_as_frmr_rsp - builds FRMR response PDU + * @skb: Address of the frame to build + * @prev_pdu: The rejected PDU frame + * @f_bit: The F bit to set in the PDU + * @vs: tx state vari value for the data link conn at the rejecting LLC + * @vr: rx state var value for the data link conn at the rejecting LLC + * @vzyxw: completely described in the IEEE Std 802.2 document (Pg 55) + * + * Builds a pdu frame as a FRMR response. + */ +void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu, + u8 f_bit, u8 vs, u8 vr, u8 vzyxw) +{ + struct llc_frmr_info *frmr_info; + u8 prev_pf = 0; + u8 *ctrl; + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_U; + pdu->ctrl_1 |= LLC_2_PDU_RSP_FRMR; + pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK; + + frmr_info = (struct llc_frmr_info *)&pdu->ctrl_2; + ctrl = (u8 *)&prev_pdu->ctrl_1; + FRMR_INFO_SET_REJ_CNTRL(frmr_info,ctrl); + FRMR_INFO_SET_Vs(frmr_info, vs); + FRMR_INFO_SET_Vr(frmr_info, vr); + prev_pf = llc_pdu_get_pf_bit(prev_pdu); + FRMR_INFO_SET_C_R_BIT(frmr_info, prev_pf); + FRMR_INFO_SET_INVALID_PDU_CTRL_IND(frmr_info, vzyxw); + FRMR_INFO_SET_INVALID_PDU_INFO_IND(frmr_info, vzyxw); + FRMR_INFO_SET_PDU_INFO_2LONG_IND(frmr_info, vzyxw); + FRMR_INFO_SET_PDU_INVALID_Nr_IND(frmr_info, vzyxw); + FRMR_INFO_SET_PDU_INVALID_Ns_IND(frmr_info, vzyxw); + skb_put(skb, sizeof(struct llc_frmr_info)); +} + +/** + * llc_pdu_init_as_rr_rsp - builds RR response pdu + * @skb: Address of the skb to build + * @f_bit: The F bit to set in the PDU + * @nr: The seq. number of the expected data PDU from the remote + * + * Builds a pdu frame as an RR response. + */ +void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_RSP_RR; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_rej_rsp - builds REJ response pdu + * @skb: Address of the skb to build + * @f_bit: The F bit to set in the PDU + * @nr: The seq. number of the expected data PDU from the remote + * + * Builds a pdu frame as a REJ response. + */ +void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_RSP_REJ; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_rnr_rsp - builds RNR response pdu + * @skb: Address of the frame to build + * @f_bit: The F bit to set in the PDU + * @nr: The seq. number of the expected data PDU from the remote + * + * Builds a pdu frame as an RNR response. + */ +void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr) +{ + struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_S; + pdu->ctrl_1 |= LLC_2_PDU_RSP_RNR; + pdu->ctrl_2 = 0; + pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK; + pdu->ctrl_1 &= 0x0F; /* setting bits 5..8 to zero(reserved) */ + pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */ +} + +/** + * llc_pdu_init_as_ua_rsp - builds UA response pdu + * @skb: Address of the frame to build + * @f_bit: The F bit to set in the PDU + * + * Builds a pdu frame as a UA response. + */ +void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit) +{ + struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); + + pdu->ctrl_1 = LLC_PDU_TYPE_U; + pdu->ctrl_1 |= LLC_2_PDU_RSP_UA; + pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK; +} + +/** + * llc_pdu_decode_pdu_type - designates PDU type + * @skb: input skb that type of it must be designated. + * @type: type of PDU (output argument). + * + * This function designates type of PDU (I, S or U). + */ +static void llc_pdu_decode_pdu_type(struct sk_buff *skb, u8 *type) +{ + struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); + + if (pdu->ctrl_1 & 1) { + if ((pdu->ctrl_1 & LLC_PDU_TYPE_U) == LLC_PDU_TYPE_U) + *type = LLC_PDU_TYPE_U; + else + *type = LLC_PDU_TYPE_S; + } else + *type = LLC_PDU_TYPE_I; +} + +/** + * llc_pdu_get_pf_bit - extracts p/f bit of input PDU + * @pdu: pointer to LLC header. + * + * This function extracts p/f bit of input PDU. at first examines type of + * PDU and then extracts p/f bit. Returns the p/f bit. + */ +static u8 llc_pdu_get_pf_bit(struct llc_pdu_sn *pdu) +{ + u8 pdu_type; + u8 pf_bit = 0; + + if (pdu->ctrl_1 & 1) { + if ((pdu->ctrl_1 & LLC_PDU_TYPE_U) == LLC_PDU_TYPE_U) + pdu_type = LLC_PDU_TYPE_U; + else + pdu_type = LLC_PDU_TYPE_S; + } else + pdu_type = LLC_PDU_TYPE_I; + switch (pdu_type) { + case LLC_PDU_TYPE_I: + case LLC_PDU_TYPE_S: + pf_bit = pdu->ctrl_2 & LLC_S_PF_BIT_MASK; + break; + case LLC_PDU_TYPE_U: + pf_bit = (pdu->ctrl_1 & LLC_U_PF_BIT_MASK) >> 4; + break; + } + return pf_bit; +} |